From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- drivers/mfd/viperboard.c | 126 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) create mode 100644 drivers/mfd/viperboard.c (limited to 'drivers/mfd/viperboard.c') diff --git a/drivers/mfd/viperboard.c b/drivers/mfd/viperboard.c new file mode 100644 index 000000000..36be8e69f --- /dev/null +++ b/drivers/mfd/viperboard.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Nano River Technologies viperboard driver + * + * This is the core driver for the viperboard. There are cell drivers + * available for I2C, ADC and both GPIOs. SPI is not yet supported. + * The drivers do not support all features the board exposes. See user + * manual of the viperboard. + * + * (C) 2012 by Lemonage GmbH + * Author: Lars Poeschel + * All rights reserved. + */ + +#include +#include +#include +#include +#include +#include + +#include +#include + +#include + + +static const struct usb_device_id vprbrd_table[] = { + { USB_DEVICE(0x2058, 0x1005) }, /* Nano River Technologies */ + { } /* Terminating entry */ +}; + +MODULE_DEVICE_TABLE(usb, vprbrd_table); + +static const struct mfd_cell vprbrd_devs[] = { + { + .name = "viperboard-gpio", + }, + { + .name = "viperboard-i2c", + }, + { + .name = "viperboard-adc", + }, +}; + +static int vprbrd_probe(struct usb_interface *interface, + const struct usb_device_id *id) +{ + struct vprbrd *vb; + + u16 version = 0; + int pipe, ret; + + /* allocate memory for our device state and initialize it */ + vb = kzalloc_obj(*vb); + if (!vb) + return -ENOMEM; + + mutex_init(&vb->lock); + + vb->usb_dev = interface_to_usbdev(interface); + + /* save our data pointer in this interface device */ + usb_set_intfdata(interface, vb); + dev_set_drvdata(&vb->pdev.dev, vb); + + /* get version information, major first, minor then */ + pipe = usb_rcvctrlpipe(vb->usb_dev, 0); + ret = usb_control_msg(vb->usb_dev, pipe, VPRBRD_USB_REQUEST_MAJOR, + VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, vb->buf, 1, + VPRBRD_USB_TIMEOUT_MS); + if (ret == 1) + version = vb->buf[0]; + + ret = usb_control_msg(vb->usb_dev, pipe, VPRBRD_USB_REQUEST_MINOR, + VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, vb->buf, 1, + VPRBRD_USB_TIMEOUT_MS); + if (ret == 1) { + version <<= 8; + version = version | vb->buf[0]; + } + + dev_info(&interface->dev, + "version %x.%02x found at bus %03d address %03d\n", + version >> 8, version & 0xff, + vb->usb_dev->bus->busnum, vb->usb_dev->devnum); + + ret = mfd_add_hotplug_devices(&interface->dev, vprbrd_devs, + ARRAY_SIZE(vprbrd_devs)); + if (ret != 0) { + dev_err(&interface->dev, "Failed to add mfd devices to core."); + goto error; + } + + return 0; + +error: + kfree(vb); + + return ret; +} + +static void vprbrd_disconnect(struct usb_interface *interface) +{ + struct vprbrd *vb = usb_get_intfdata(interface); + + mfd_remove_devices(&interface->dev); + usb_set_intfdata(interface, NULL); + kfree(vb); + + dev_dbg(&interface->dev, "disconnected\n"); +} + +static struct usb_driver vprbrd_driver = { + .name = "viperboard", + .probe = vprbrd_probe, + .disconnect = vprbrd_disconnect, + .id_table = vprbrd_table, +}; + +module_usb_driver(vprbrd_driver); + +MODULE_DESCRIPTION("Nano River Technologies viperboard mfd core driver"); +MODULE_AUTHOR("Lars Poeschel "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1